• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of pnasPNASInfo for AuthorsSubscriptionsAboutThis Article
Proc Natl Acad Sci U S A. Nov 1, 1993; 90(21): 9852–9856.

Crystal structure of a bacterial sialidase (from Salmonella typhimurium LT2) shows the same fold as an influenza virus neuraminidase.


Sialidases (EC or neuraminidases) remove sialic acid from sialoglycoconjugates, are widely distributed in nature, and have been implicated in the pathogenesis of many diseases. The three-dimensional structure of influenza virus sialidase is known, and we now report the three-dimensional structure of a bacterial sialidase, from Salmonella typhimurium LT2, at 2.0-A resolution and the structure of its complex with the inhibitor 2-deoxy-2,3-dehydro-N-acetylneuraminic acid at 2.2-A resolution. The viral enzyme is a tetramer; the bacterial enzyme, a monomer. Although the monomers are of similar size (approximately 380 residues), the sequence similarity is low (approximately 15%). The viral enzyme contains at least eight disulfide bridges, conserved in all strains, and binds Ca2+, which enhances activity; the bacterial enzyme contains one disulfide and does not bind Ca2+. Comparison of the two structures shows a remarkable similarity both in the general fold and in the spatial arrangement of the catalytic residues. However, an rms fit of 3.1 A between 264 C alpha atoms of the S. typhimurium enzyme and those from an influenza A virus reflects some major differences in the fold. In common with the viral enzyme, the bacterial enzyme active site consists of an arginine triad, a hydrophobic pocket, and a key tyrosine and glutamic acid, but differences in the interactions with the O4 and glycerol groups of the inhibitor reflect differing kinetics and substrate preferences of the two enzymes. The repeating "Asp-box" motifs observed among the nonviral sialidase sequences occur at topologically equivalent positions on the outside of the structure. Implications of the structure for the catalytic mechanism, evolution, and secretion of the enzyme are discussed.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.5M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Corfield T. Bacterial sialidases--roles in pathogenicity and nutrition. Glycobiology. 1992 Dec;2(6):509–521. [PubMed]
  • Pereira ME, Mejia JS, Ortega-Barria E, Matzilevich D, Prioli RP. The Trypanosoma cruzi neuraminidase contains sequences similar to bacterial neuraminidases, YWTD repeats of the low density lipoprotein receptor, and type III modules of fibronectin. J Exp Med. 1991 Jul 1;174(1):179–191. [PMC free article] [PubMed]
  • Vimr ER, Lawrisuk L, Galen J, Kaper JB. Cloning and expression of the Vibrio cholerae neuraminidase gene nanH in Escherichia coli. J Bacteriol. 1988 Apr;170(4):1495–1504. [PMC free article] [PubMed]
  • Galen JE, Ketley JM, Fasano A, Richardson SH, Wasserman SS, Kaper JB. Role of Vibrio cholerae neuraminidase in the function of cholera toxin. Infect Immun. 1992 Feb;60(2):406–415. [PMC free article] [PubMed]
  • Taylor G, Vimr E, Garman E, Laver G. Purification, crystallization and preliminary crystallographic study of neuraminidase from Vibrio cholerae and Salmonella typhimurium LT2. J Mol Biol. 1992 Aug 20;226(4):1287–1290. [PubMed]
  • Chong AK, Pegg MS, von Itzstein M. Influenza virus sialidase: effect of calcium on steady-state kinetic parameters. Biochim Biophys Acta. 1991 Mar 8;1077(1):65–71. [PubMed]
  • Roggentin P, Rothe B, Kaper JB, Galen J, Lawrisuk L, Vimr ER, Schauer R. Conserved sequences in bacterial and viral sialidases. Glycoconj J. 1989;6(3):349–353. [PubMed]
  • Tulip WR, Varghese JN, Baker AT, van Donkelaar A, Laver WG, Webster RG, Colman PM. Refined atomic structures of N9 subtype influenza virus neuraminidase and escape mutants. J Mol Biol. 1991 Sep 20;221(2):487–497. [PubMed]
  • Varghese JN, Colman PM. Three-dimensional structure of the neuraminidase of influenza virus A/Tokyo/3/67 at 2.2 A resolution. J Mol Biol. 1991 Sep 20;221(2):473–486. [PubMed]
  • Burmeister WP, Ruigrok RW, Cusack S. The 2.2 A resolution crystal structure of influenza B neuraminidase and its complex with sialic acid. EMBO J. 1992 Jan;11(1):49–56. [PMC free article] [PubMed]
  • Wang BC. Resolution of phase ambiguity in macromolecular crystallography. Methods Enzymol. 1985;115:90–112. [PubMed]
  • Jones TA, Zou JY, Cowan SW, Kjeldgaard M. Improved methods for building protein models in electron density maps and the location of errors in these models. Acta Crystallogr A. 1991 Mar 1;47(Pt 2):110–119. [PubMed]
  • Hoyer LL, Hamilton AC, Steenbergen SM, Vimr ER. Cloning, sequencing and distribution of the Salmonella typhimurium LT2 sialidase gene, nanH, provides evidence for interspecies gene transfer. Mol Microbiol. 1992 Apr;6(7):873–884. [PubMed]
  • Brünger AT. Crystallographic refinement by simulated annealing. Application to a 2.8 A resolution structure of aspartate aminotransferase. J Mol Biol. 1988 Oct 5;203(3):803–816. [PubMed]
  • Varghese JN, McKimm-Breschkin JL, Caldwell JB, Kortt AA, Colman PM. The structure of the complex between influenza virus neuraminidase and sialic acid, the viral receptor. Proteins. 1992 Nov;14(3):327–332. [PubMed]
  • Hoyer LL, Roggentin P, Schauer R, Vimr ER. Purification and properties of cloned Salmonella typhimurium LT2 sialidase with virus-typical kinetic preference for sialyl alpha 2----3 linkages. J Biochem. 1991 Sep;110(3):462–467. [PubMed]
  • Burmeister WP, Henrissat B, Bosso C, Cusack S, Ruigrok RW. Influenza B virus neuraminidase can synthesize its own inhibitor. Structure. 1993 Sep 15;1(1):19–26. [PubMed]
  • Warner TG, Harris R, McDowell R, Vimr ER. Photolabelling of Salmonella typhimurium LT2 sialidase. Identification of a peptide with a predicted structural similarity to the active sites of influenza-virus sialidases. Biochem J. 1992 Aug 1;285(Pt 3):957–964. [PMC free article] [PubMed]
  • Messer M. Identification of N-acetyl-4-O-acetylneuraminyl-lactose in Echidna milk. Biochem J. 1974 May;139(2):415–420. [PMC free article] [PubMed]
  • von Itzstein M, Wu WY, Kok GB, Pegg MS, Dyason JC, Jin B, Van Phan T, Smythe ML, White HF, Oliver SW, et al. Rational design of potent sialidase-based inhibitors of influenza virus replication. Nature. 1993 Jun 3;363(6428):418–423. [PubMed]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences


Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...